Last August and September, the CNPSSD email list hosted a long discussion about seed “bombs,” or rather seed balls. At the September meeting, a man came forward to provide his seed balls free to CNPSSD as a demo. They reportedly contained the seeds of ten native plant species.

I have a dish on my patio where I grow native annuals, so I dropped the seed ball in that dish. My first experiences with it are chronicled in a previous blog entry. Now it’s eleven months later, and I decided to end the project.

As can be seen in the pictures below, there are two species now growing in that dish: some sort of italian ryegrass (Lolium multiflorum) and sweet alyssum (Lobularia maritima). The ball also grew a California poppy (Eschscholzia californica) in the spring, and it flowered and died.

Seed ball finale. The left picture is the dish, the right picture shows the remnants of the seed ball with the plants growing out of it. Click on the pictures to enlarge them.

Today I took the pictures, ended the experiment by ripping out the weeds, roots and all (they’d rooted through the pot), and planted a Dudleya pulverulenta that needed a new location.

This experiment has a couple of important learning points: one is that seed source is critical. Even if the seed ball maker used what he thought were nothing but California native plants, the evidence unequivocally says there were weed seeds in that ball. The second is that only two plants will grow from a ball at a time (the poppy came up and died before the grass grew). If there were 100 seeds in that ball, then 97% failed.

For do-it-yourself seedball makers: Do realize that you can spread weeds with seed balls. If you insist on making seed balls for a project, ideally you should collect your own seed, assuming you can identify the plants correctly. A second choice is to buy pure seed from a reputable dealer. Good dealers will tell you how much weed seed is in their mix. That number is rarely zero, despite everyone’s best efforts.

If you buy a packet of “wildflower seed,” for your seed ball mix, you have to realize that “WILDFLOWER” is an industry term for a certain group of annual plants, some of which are weeds in California. You actually have to look at the species list to see what is in the packet, and to make sure they are all California natives. If reading such a list perturbs you, don’t use wildflower seed packets.

It is ALWAYS possible for weed seed to get mixed in, simply by accident. If you’re not planning on weeding a site after you seed ball it, my advice is not to throw seed balls. We have enough weeds in this county already, and we don’t need people spreading more.

At the CNPS-SD plant sale last weekend, I helped Amy Huie sell seeds (Hi Amy!). We had this little legalistic statement on the seed packets, about how they were for landscaping use only, not for restoration. Now as far as I know, that little phrase on the seed packet is a reminder that the seeds came from a commercial vendor, and we have no idea where they were harvested. The idea is that people can do whatever they want on their private property, but we’re not going to recommend that they scatter them in the wild.

One of the customers said, “what does this notice mean? What if we ARE planning on using them for restoration?” I questioned her, and it turned out she wanted to scatter the seeds (including California poppies) in a nearby park. According to her, it was all empty, with Eucalyptus and stuff, and (as I found out through more questions), lots of mustard. She wanted to make it more natural, and she didn’t like that we were being all legalistic. I guess she felt we were criticizing her environmental inclinations, her desire to be a Ninja Do-Gooder in its latest, most fashionable phase: the guerrilla gardener.

We’re seeing more of that guerrilla gardening thing around this year. For example: seed balls, mistakenly called seed bombs. At the last CNPS meeting, a guy handed out seed balls, after he inadvertently sparked an online discussion because someone implied that his balls contained invasives. For the record, those balls don’t contain invasives, just 8-10 species of California native plants, and at least a hundred seeds per ball.

I took one of those balls home and pitched it in the pot I grow native annuals in. The ball was an inch round of solid red clay and it didn’t shatter as it was supposed to. It bounced (surprise surprise) . The thunderstorms a few weeks ago triggered something to germinate, and at least 10 seedlings sprouted right next to each other. A week later, they were all dead. The clay had dried out, and they could not reach the soil. With the current rains, something else is sprouting on top of that ball, but I’m not holding out much more hope for it either.

Even if something does survive, there’s only space for one plant to grow in that ball’s footprint, so 99% of his seeds are wasted at the outset, never mind the ones that will strangle each other through competition. This ball was badly designed, but I’m having fun watching it, just to understand how it’s failing, in detail. I recommend this exercise to anyone who (like me) thinks seed balls are cool. Reality is cool too, and she’s a better teacher.

And so it goes with guerrilla gardening. Seed balls are fun, making them keeps little fingers busy, and since everyone’s talking about them, they must work, right? Moreover, you get to Stick it To Da Man and Help Mother Nature by throwing something over a fence, and that just feels right. Especially if, unlike me, you’re optimistic.

Does it work? Well, that’s the awkward part: I’ve heard one story of seed balls used to sow evening primrose into a canyon restoration. So far that’s it. If you’ve got more stories, please share them.

As for designing seed balls, I’ve started telling people to a) read The One Straw Revolution so that you can see how seed balls were originally made and used (hint, it’s not quite what we’re doing now), b) to use fewer seeds and 1-2 species per ball, so that something has a chance of making it (unless you like wasting seed, which I don’t), and c) if you want that ball to shatter, don’t make it out of solid clay. Otherwise, you’re going to make a seed bomb, which, as you might guess, is going to bomb. Badly.

And while it’s nice to keep little fingers busy making seed balls, maybe we should be teaching little fingers how to grow plants successfully? That’s a little harder, but I think the lesson (“Wow! Mommy taught me how to grow plants. She’s really smart.”) might be more useful than what they’re learning from seed ball making (“ooh, I can make a mess, and it’s fun, but the plants didn’t grow.”) Just saying.

As for the would-be guerrilla gardener from last Saturday, I learned from her that her partner was helping collect seeds for CNPS. So I gently suggested that, while CNPS could never condone trespassing or doing things without permission, if they were insistent on doing something about that park, they should collect seeds from the nearby canyons and plant them. If they followed those very nice collecting guidelines that CNPS has. And after they got the mustard under control.

She didn’t purchase many seeds, and I feel a little bad about depriving CNPS of her money. Then again, do we really need more California poppies in our local parks? It’s not like they’re locally native.